Millennium Space Systems is now developing all 12 satellites for the initial configuration of the Space Force’s missile warning/tracking constellation in medium Earth orbit. (Courtesy Image: Millennium Space Systems)

WASHINGTON — Space Force Space Systems Command (SSC) today announced a $386 million award to Millennium Space Systems for six satellites to fill out the baseline configuration of its future missile warning constellation in medium Earth orbit (MEO) — in effect replacing an earlier contract with RTX that was terminated in June. 

The six satellites will be launched to a different orbital plane than the first six birds in SSC’s planned Epoch 1, also being built by Millennium under a contract granted last November.

“This action successfully completes the Epoch 1 program’s intent to deliver two planes of satellites for a total of 12 space vehicles.” SSC said in a press release today. The delivery of the first Epoch 1 birds is planned for the end of fiscal 2026, the release added, “and the second plane is expected in early FY28.”

Each spiral of satellites under the Resilient Missile Warning/Missile Tracking — Medium Earth Orbit program are called Epochs, and will be delivered every two to three years.

Epoch 1 in essence transitions the SSC’s 2021 study of MEO-based missile warning capabilities, first reported by Breaking Defense, to a program of record with Raytheon Intelligence & Space, now RTX, and Boeing’s Millennium Space Systems contracted in January 2023 to build MEO MW/MT Epoch 1 prototypes. But when RTX’s effort fell behind schedule and over budget, SSC terminated the contract.

“When one of our two industry partners struggled with delivering on cost and schedule, we were able to quickly pivot and still maintain program progress by turning to the performing vendor,” Col. Rob Davis, program executive officer for SSC’s Space Sensing Directorate, told the Space Industry Days conference in Los Angeles today.

Speaking to reporters following his presentation, Davis explained that while RTX had been on contract for three satellites, those were larger birds in a higher altitude and a different design than those now being developed by Millennium. The capability being provided, however, “so everything balances out there,” he said.

Epoch 2, the next configuration of MEO birds, is expected to be up and running circa 2029, and will provide “initial warfighting capability,” the SSC press release explains. The command released a Request for Prototype Proposal for Epoch 2 in August.